Objective: To investigate the relationship between the expression of four mismatch repair proteins (MLH1, MSH2, MSH6 and PMS2) and NTRK genetic fusions in colorectal cancer. Methods: The paraffin-embedded tissue blocks of 830 cases of colorectal cancer were collected at the Affiliated Drum Tower Hospital, Nanjing University Medical School, China, from 2015 to 2019. Immunohistochemical and fluorescence in situ hybridization(FISH) method were used respectively to detect the expression of mismatch repair proteins and the break-apart of NTRKs; and the relationship between the expression of mismatch repair proteins and the NTRK genetic fusions was analyzed. Results: The overall mismatch repair protein deficiency (dMMR) rate was 9.88% (82/830), the mismatch repair proteins proficiency (pMMR) rate was 90.12%(748/830). The total deficiency rate of MLH1 protein was 9.04% (75/830), hPMS2 protein deficiency rate was 9.04% (75/830), MSH2 protein deficiency rate was 2.53% (21/830), MSH6 protein deficiency rate was 4.10% (34/830), the deficiency rate of synchronous MLH1 and PMS2 were 8.67% (72/830) and the deficiency rate of synchronous MSH2 and MSH6 were 2.17% (18/830). The dMMR group was associated with tumor location, different histological subgroups, tumor differentiation, AJCC stage and N stage (P<0.05). There were six cases (7.32%) carrying NTRK fusion by FISH among the 82 cases of dMMR, but only seven cases (0.94%) carrying NTRK fusion among the 748 cases of PMMR. The NTRKs translocation by FISH in all 13 cases were further confirmed by next generation sequencing. Among the clinicopathological characteristics, only differentiation showed significant difference between NTRK fusion positive and negative groups (P<0.05). More importantly, NTRK fusion was enriched in dMMR group (7.32% vs. 0.94%). Conclusion: In dMMR colorectal cancer group, the prevalence of NTRK fusion is higher than that in pMMR group.
Colonic Neoplasms ; Colorectal Neoplasms/genetics* ; DNA Mismatch Repair/genetics* ; Humans ; In Situ Hybridization, Fluorescence ; Mismatch Repair Endonuclease PMS2/metabolism* ; MutL Protein Homolog 1/metabolism* ; MutS Homolog 2 Protein/metabolism*

Objective: To investigate the molecular classification and clinicopathological features of endometrial carcinoma(EC). Methods: One hundred cases of EC diagnosed in the Department of Pathology, Tianjin Central Hospital of Gynecology and Obstetrics from November 2020 to November 2021 were selected. Sanger sequencing and immunohistochemical staining were used for molecular classification according to the 5th WHO classification. The clinicopathological characteristics of each molecular subtype was analyzed. Results: The 100 EC patients had a mean age of 53 years (range 26 to 72 years). There were 10 cases of POLE mutation (POLE mut), including two cases (2/10) of "binary-classifier" EC, two cases (2/10) of FIGO Grade 3 endometrioid endometrial carcinoma (G3-EEC), and three cases (3/10) of other high-grade subtypes. There were 38 cases of mismatch repair deficiency (dMMR), including one case (1/38, 2.6%) of "binary-classifier" EC and 36 cases (36/38, 94.7%) were EEC. Twenty-one cases (21/38, 55.3%) showed simultaneous loss of expression of MLH1 and PMS2, and 20 cases (20/21, 95.2%) were positive for MLH1 methylation, indicating that they were sporadic EC. Six patients (6/38, 15.8%) were tested for germline detection of Lynch syndrome (LS) related genes, and one patient was LS-related EC. There were 44 cases of non-specific molecular profile (NSMP), including 34 cases (34/44, 77.3%) of G1-2 EEC and seven cases (7/44, 15.9%) of G3-EEC. There were eight cases of p53 abnormality (p53 abn), including four cases (4/8) of G3-EEC, two cases (2/8) of other high-grade subtypes, and one patient had hereditary breast cancer and ovarian cancer syndrome. Conclusions: Correct interpretation of POLE mutation, MMR and p53 immunohistochemistry is the key of molecular classification. The interpretation must strictly follow standard diagnostic procedures and specifications to ensure the accuracy of molecular classification.
Adult ; Aged ; Carcinoma, Endometrioid/genetics* ; Colorectal Neoplasms, Hereditary Nonpolyposis/pathology* ; DNA Mismatch Repair ; Endometrial Neoplasms/pathology* ; Female ; Humans ; Middle Aged ; Mismatch Repair Endonuclease PMS2/metabolism* ; MutL Protein Homolog 1/metabolism* ; Tumor Suppressor Protein p53/metabolism*

Objective: To analyze the expression of mismatch repair (MMR) protein and the EB virus infection in gastric adenocarcinoma, and to examine the association of MMR expression and EB virus infection with clinicopathological parameters. Methods: A case-control study was performed. Clinicopathological data of patients who was pathologically diagnosed as gastric adenocarcinoma, received radical gastrectomy and had complete clinicopathological data from August 2017 to April 2020 in Tianjin Medical University Cancer Institute and Hospital were retrospectively collected and analyzed. The immunohistochemistry (IHC) of MMR proteins and in situ hybridization (ISH) of Epstein-Barr virus encoded RNA (EBER) were reviewed. The associations of MMR and EBER results with clinicopathological parameters were analyzed. The main observations of the study were MMR and EBER expression, and association of MMR and EBER results with clinicopathological parameters. Results: Eight hundred and eighty-six patients were enrolled, including 98 patients who received preoperative neoadjuvant chemoradiotherapy. Of 886 patients, 613 (69.2%) were males and the median age was 60 (22-83) years; 831 (93.8%) were mismatch repair proficiency (pMMR), and 55 (6.2%) were mismatch repair deficiency (dMMR). In dMMR group, 47 cases (85.5%) had the deficiency of both MLH1 and PMS2, 1 case (1.8%) had the deficiency of both MSH2 and MSH6, 4 cases (7.3%) had the deficiency only in PMS2, 2 cases (3.6%) had the deficiency only in MSH6, and 1 case (1.8%) had the deficiency only in MSH2. The deficiency rates of PMS2, MLH1, MSH6 and MSH2 were 5.8% (51/886), 5.3% (47/886), 0.3% (3/886) and 0.2% (2/886), respectively. Among the 871 cases with EBER results, 4.9% (43/871) were positive EBER. Univariate analysis showed that dMMR was more frequently detected in female patients (χ(2)=10.962, P=0.001), cancer locating in the antrum (χ(2)=9.336,P=0.020), Lauren intestinal type (χ(2)=9.718, P=0.018), stage T3 (χ(2)=25.866, P<0.001) and TNM stage II (χ(2)=15.470, P=0.002). The ratio of dMMR was not significantly associated with age, tumor differentiation, histological type, lymph node metastasis, distant metastasis or Her-2 immunohistochemical score (all P>0.05). Compared with negative EBER, positive EBER was more frequent in male patients (χ(2)=9.701, P=0.002), cancer locating in gastric fundus and corpus (χ(2)=17.964, P<0.001), gastric cancer with lymphoid stroma (χ(2)=744.073, P<0.001) and poorly differentiated cancer (χ(2)=13.739, P=0.010). Positive EBER was not significantly associated with age, depth of invasion, lymph node metastasis, distant metastasis, TNM stage or Her-2 immunohistochemical score (all P>0.05). In addition, all dMMR cases were EBER negative, and all cases of positive EBER were pMMR. Conclusions: The positive EB virus status is mutually exclusive with dMMR, indicating that different molecular subtypes of gastric adenocarcinoma are involved in different molecular pathways in tumorigenesis and progression. The overlapping of dMMR or positive EBER status and positive Her-2 expression is found in some cases of gastric adenocarcinoma. Patients with gastric adenocarcinoma after radical surgery should be tested for MMR status if they are female, the tumor locates in gastric antrum, the TNM staging is stage II or T3, or if the Lauren classification is intestinal type. And if patients are male, the tumor locates in the gastric fundus and corpus, the cancer is lymphoid stroma, or poor differentiated, the expression of EBER should be detected. Results of our study may provide evidence for further decision-making of clinical treatment.
Adenocarcinoma ; Case-Control Studies ; DNA Mismatch Repair ; Epstein-Barr Virus Infections ; Female ; Herpesvirus 4, Human ; Humans ; Male ; Middle Aged ; Mismatch Repair Endonuclease PMS2/metabolism* ; MutL Protein Homolog 1/genetics* ; MutS Homolog 2 Protein/metabolism* ; Retrospective Studies ; Stomach Neoplasms

OBJECTIVETo explore the relationship between DNA mismatch repair (MMR) and clinicopathologic features and prognosis in patients with stages II and III colon cancers.

METHODSThe clinical and pathological data of 440 patients with stage II/III colon cancer after radical resection were retrospectively reviewed and analyzed. Immunohistochemical staining was used to assess the expression of MMR proteins (MLH1, MSH2, MSH6 and PMS2), and the correlation between DNA MMR and clinicopathological features and prognosis of colon cancers was analyzed.

RESULTSOf the 440 tumor samples tested for DNA mismatch repair status, 90 (20.5%) demonstrated defective DNA mismatch repair and 350 (79.5%) had proficient DNA mismatch repair. Defective DNA mismatch repair (dMMR) was associated with young patients (≤ 60), proximal colon cancer, stage II, poorly differentiated adenocarcinoma and mucinous adenocarcinoma (P<0.05 for all). Among the 440 patients, 126 (28.6%) cases had recurrence or metastasis and 93 (21.1%) died during the median follow-up of 61.0 months. The five-year disease-free survival (DFS) rate was 82.2% among the patients with tumor exhibiting dMMR, significantly higher than that in patients with tumors exhibiting pMMR (68.9%, P=0.02). The univariate and mutlivariate analyses showed that the MMR status is an independent factor affecting 5-year disease-free survival and overall survival (OS) in colon cancer patients (P<0.05 for both).

CONCLUSIONSDefective DNA mismatch repair (dMMR) is associated with patients with proximal colon cancer, stage II and poorly defferentiated adenocarcinoma and mucinous adenocarcinoma. The prognosis for patients with dMMR is better than those with pMMR. dMMR may be a useful biomarker for the prognosis of colon cancer.

Adaptor Proteins, Signal Transducing ; metabolism ; Adenocarcinoma ; genetics ; metabolism ; mortality ; pathology ; Adenocarcinoma, Mucinous ; genetics ; metabolism ; mortality ; pathology ; Adenosine Triphosphatases ; metabolism ; Age Factors ; Analysis of Variance ; Colonic Neoplasms ; genetics ; metabolism ; mortality ; pathology ; DNA Mismatch Repair ; DNA Repair Enzymes ; metabolism ; DNA-Binding Proteins ; metabolism ; Disease-Free Survival ; Humans ; Mismatch Repair Endonuclease PMS2 ; MutL Protein Homolog 1 ; MutS Homolog 2 Protein ; metabolism ; Neoplasm Recurrence, Local ; Nuclear Proteins ; metabolism ; Prognosis ; Retrospective Studies ; Survival Rate

OBJECTIVETo evaluate the application of mismatch repair (MMR) genes proteins expression to screen for Lynch syndrome in colorectal cancer patients.

METHODSOne hundred consecutive colorectal cancers cases collected from 2012 to 2013 were tested immunohistochemically for the protein expression of MLH1, MSH2, MSH6 and PMS2, and also by the ARMS method for the mutation status of BRAF genes in those cases lacking protein expression for MLH1.

RESULTSThe result of MMR immunocytochemistry showed that nine of 100 cases lacked MMR protein expression, including three cases each that were MLH1-/PMS2- and MSH2-/MSH6- respectively, two cases were MLH6- and one case was PMS2-; overall, the majority of these cases lacked protein expression of MLH1 and MSH2. The BRAF genes mutation test showed one case of mutation, indicating that the patient might have MLH1 gene methylation as a result of the mutation of BRAF genes, and that was a sporadic case. The age of onset for patients lacking MMR protein expression was lower than patients with sporadic colorectal cancer (P = 0.011). Colorectal cancers associated with the lack of MMR protein expression mostly occurred in the right colon (P = 0.001), and histomorphologically were often accompanied by mucinous adenocarcinoma (P = 0.010) and tumor lymphocytic infiltration.

CONCLUSIONImmunohistochemical staining for MMR proteins in patients with colorectal cancer, accompanied by testing for BRAF genes mutation, may be an effective approach to screen for Lynch syndrome.

Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Colorectal Neoplasms, Hereditary Nonpolyposis ; diagnosis ; genetics ; DNA Mismatch Repair ; Humans ; Immunohistochemistry ; MutL Protein Homolog 1 ; Mutation ; Nuclear Proteins ; genetics ; metabolism ; Proto-Oncogene Proteins B-raf ; genetics ; metabolism

Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Adenosine Triphosphatases ; genetics ; metabolism ; DNA Mismatch Repair ; DNA Repair Enzymes ; genetics ; metabolism ; DNA-Binding Proteins ; genetics ; metabolism ; Endometrial Neoplasms ; etiology ; genetics ; metabolism ; pathology ; Female ; Genetic Predisposition to Disease ; Humans ; Lynch Syndrome II ; complications ; genetics ; metabolism ; pathology ; Mismatch Repair Endonuclease PMS2 ; MutL Protein Homolog 1 ; MutS Homolog 2 Protein ; genetics ; metabolism ; Mutation ; Nuclear Proteins ; genetics ; metabolism

OBJECTIVETo analyze immunophenotypes and gene mutations of colorectal precancerous lesions and adenocarcinoma, and to compare the difference of carcinogenetic mechanisms between the two precancerous lesions.

METHODSFifty-three cases of colorectal serrated lesions including 30 hyperplastic polyps, 20 sessile serrated adenomas (SSA) and 3 mixed polyps were collected from January 2006 to June 2012.Forty-five cases of traditional adenomas and 50 cases of colorectal adenocarcinomas were also recruited. Thirty hyperplastic polyps, 20 cases of SSA, 3 mixed polyps and 45 traditional adenomas were investigated by immunohistochemistry for the expression of DNA mismatch repair (MMR) proteins (MLH1, MSH2 and MSH6) and DNA methyltransferase MGMT. Mutations of KRAS, BRAF and PIK3CA genes in 10 cases of SSAs, 10 traditional adenomas, 1 mixed polyps and 50 colorectal adenocarcinomas were analyzed by PCR followed by direct Sanger sequencing.

RESULTS(1) Only 3 cases of hyperplastic polyps lost MLH1 expression, and none of SSAs or traditional adenomas showed loss of MLH1. The negative expression rates of MSH2, MSH6 and MGMT in hyperplastic polyps and SSA were significantly higher than those of traditional adenomas. (2) KRAS mutation was found in 5/10 cases of SSAs, 5/10 traditional adenomas and 1/1 mixed polyps. (3) Colorectal adenocarcinomas harbored the mutations of KRAS (48%, 24/50), BRAF (6%, 3/50) and PIK3CA (4%, 2/50).

CONCLUSIONSImmunophenotypic and gene mutation profiles are different between colorectal serrated lesion and traditional adenoma. Alterations of MMR and MGMT expression play important roles in the pathogenesis of "serrated neoplasm". KRAS mutation is a significant genetic change in the early phase of colorectal carcinogenesis.

Adaptor Proteins, Signal Transducing ; metabolism ; Adenocarcinoma ; genetics ; metabolism ; Adenoma ; genetics ; metabolism ; Aged ; Class I Phosphatidylinositol 3-Kinases ; Colonic Polyps ; genetics ; metabolism ; Colorectal Neoplasms ; genetics ; metabolism ; DNA Mismatch Repair ; DNA Modification Methylases ; metabolism ; DNA Repair Enzymes ; metabolism ; DNA, Neoplasm ; metabolism ; DNA-Binding Proteins ; metabolism ; Female ; Humans ; Hyperplasia ; Immunophenotyping ; Male ; Middle Aged ; MutL Protein Homolog 1 ; MutS Homolog 2 Protein ; metabolism ; Nuclear Proteins ; metabolism ; Phosphatidylinositol 3-Kinases ; genetics ; Point Mutation ; Precancerous Conditions ; genetics ; metabolism ; Proto-Oncogene Proteins ; genetics ; Proto-Oncogene Proteins B-raf ; genetics ; Proto-Oncogene Proteins p21(ras) ; Sequence Analysis, DNA ; Tumor Suppressor Proteins ; metabolism ; ras Proteins ; genetics

OBJECTIVETo investigate the aberrant promoter methylation of hMLH1 gene promoter and its clinical significance in papillary thyroid cancer (PTC).

METHODSmethylation of hMLH1 gene promoter in the cancer tissue and matched tumor-adjacent normal tissue of 152 PTC patients were detected by real-time methylation specific PCR (qMSP). The relationship between the methylation of hMLH1 gene promoter and clinicopathological features was analyzed.

RESULTSThe methylation rate of hMLH1 gene promoter in cancer tissues was 37.5% (57/152), of which 33 cases were totally methylated and 24 cases were partially methylated. The methylation rate of adjacent normal tissues was 5.3% (8/152)(all were partially methylated). The methylation rate of PTC tissues was significantly higher than that in the tumor-adjacent normal tissue (P < 0.01). The promoter methylation of hMLH1 gene in PTC was significantly correlated with age, size and number of the primary lesion, local invasion, T stage and lymph node metastasis (P < 0.05) , but not correlated with gender and clinical stage (P > 0.05).

CONCLUSIONPromoter methylation of hMLH1 gene is a common molecular event in PTC tissue, and it is significantly correlated with the progression of PTC.

Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Adolescent ; Adult ; Age Factors ; Aged ; Carcinoma ; genetics ; metabolism ; pathology ; Carcinoma, Papillary ; DNA Methylation ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Lymphatic Metastasis ; Male ; Middle Aged ; MutL Protein Homolog 1 ; Neoplasm Invasiveness ; Neoplasm Staging ; Nuclear Proteins ; genetics ; metabolism ; Promoter Regions, Genetic ; genetics ; Thyroid Neoplasms ; genetics ; metabolism ; pathology ; Tumor Burden ; Young Adult

OBJECTIVETo explore whether the abnormality of hMLH1 gene may be an early event of carcinogenesis in rectal carcinoma, and to evaluate the diagnostic value in differentiation between intraepithelial neoplasm and early stage of colorectal carcinoma.

METHODSThe expression of hMLH1 protein in 28 cases with early invasive rectal carcinoma(EIRC), 36 cases with rectal intraepithelial neoplasm(RIEN), and 30 cases with normal rectal mucosa(NRM) which were collected through surgical operations were detected by PV-9000 immunohistochemical method.

RESULTSThe positive expression rates of hMLH1 protein were 100%(30/30), 77.8%(28/36), and 39.3%(11/28) in NRM, RIEN, and EIRC respectively. The difference was statistically significant between RIEN and EIRC(P=0.002), and the difference was also statistically significant between RIEN and NRM(P=0.006). The positive expression of hMLH1 was not related to age, gender, tumor maximum diameter, dysplasia, tumor types, and distance from the anal verge in RIEV group(P>0.05). In EIRC group, hMLH1 was associated with tumor differentiation(P<0.05).

CONCLUSIONhMLH1 gene deletion may be an early event during carcinogenesis of rectal carcinoma, which may be useful in differentiation of intraepithelial neoplasm from early rectal carcinoma.

Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Adult ; Aged ; Aged, 80 and over ; Carcinoma in Situ ; diagnosis ; metabolism ; Early Detection of Cancer ; Female ; Humans ; Male ; Middle Aged ; MutL Protein Homolog 1 ; Nuclear Proteins ; genetics ; metabolism ; Rectal Neoplasms ; diagnosis ; metabolism

Adaptor Proteins, Signal Transducing ; metabolism ; Adenocarcinoma, Clear Cell ; genetics ; metabolism ; pathology ; surgery ; Adenosine Triphosphatases ; metabolism ; Age Factors ; Carcinoma, Endometrioid ; genetics ; metabolism ; pathology ; surgery ; Colorectal Neoplasms, Hereditary Nonpolyposis ; genetics ; metabolism ; pathology ; surgery ; Cystadenocarcinoma, Serous ; genetics ; metabolism ; pathology ; surgery ; DNA Mismatch Repair ; DNA Repair Enzymes ; metabolism ; DNA-Binding Proteins ; metabolism ; Endometrial Neoplasms ; genetics ; metabolism ; pathology ; surgery ; Female ; Humans ; Mismatch Repair Endonuclease PMS2 ; MutL Protein Homolog 1 ; MutS Homolog 2 Protein ; metabolism ; Neoplasms, Multiple Primary ; genetics ; metabolism ; pathology ; surgery ; Nuclear Proteins ; metabolism